检索结果-南通市图书馆

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

低温比热的测量

真空与低温 1984年第2期 58-68页

作者： g.r.stewart 冯维仪

引言低温比热的测量揭示了大量的关于材料晶格及电子性能方面的信息。还有助于研究材料中转变(例如,磁、超导、结构),在某些情况下,只有用此方法才能确定,用其它方法观察到的转变是大量材料的特性,还是由于少数第二相的存在的结果。70年... 详细信息

引言低温比热的测量揭示了大量的关于材料晶格及电子性能方面的信息。还有助于研究材料中转变(例如,磁、超导、结构),在某些情况下,只有用此方法才能确定,用其它方法观察到的转变是大量材料的特性,还是由于少数第二相的存在的结果。70年前,人们就已经完成了大试样(约10克)的低温比热测量。Nernst 和 Lindemann 在1911年就曾指出他们

关键词：低温比热测量温度计绝热法特斯拉比特超导磁体比热温度测量仪表超导器件热力学性质时间常数法同步放大器

Approach for C_(1)to C_(2)products commencing from carbon dioxide:A brief review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Petroleum 2024年第3期10卷 373-398页

作者： g.r.Dey radiation and Photochemistry Division Bhabha Atomic Research CentreTrombayMumbai 400085India Homi Bhabha National Institute AnushaktinagarMumbai 400094India

The carbon dioxide(CO_(2))conversion to useable compounds remains a great contest to scientists,engineers,and environmentalists with regard to the reverse of the oxidative degradation of *** conversion is essential for the development of complementary fuels and raw materials for various industries,which in turn will help in avoiding the drastic increase in tropospheric temperature due to greenhouse effect leading to global *** solar energy is the earth's essential power source along with the other various forms of energy for example fossil fuels,hydropower,wind,and biomaterials,*** final goal is to establish the artificial photosynthesis,which can be replicated thru various chemical reduction techniques of CO_(2)by employing appropriate photo-,thermal-and electro-catalysts in order to produce different one carbon atom(C_(1))and higher carbon atoms containing ***,the utilization of clean and sustainable CO_(2)towards high-value products is of great interest today due to the recognized environmental worries and subsequent lessening of the fossil fuels utilization load to meet the energy demand of *** way,solar energy can directly and/or indirectly be altered and stored in chemical energy form for industrial as well as societal *** this article our endeavor is to summarize the advances in CO_(2)chemical reduction research area till date especially in free radical-based methods such as electrochemical,photochemical and plasma chemical for the development of carbon species up to two carbon(C_(2))atoms containing products perceived in the chemical reduction of CO_(2).The author hopes that this piece of work will be helpful to researchers and readers who are focused on the field of CO_(2).

关键词： Photocatalysis Electrocatalysis Plasmolysis Thermolysis Carbon dioxide Chemical reduction

Control system design for a pressure-tube-type supercritical water-cooled nuclear reactor via a higher order sliding mode method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： M.Hajipour g.r.Ansarifar Department of Nuclear Engineering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

Nuclear power plants exhibit non-linear and time-variable ***,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWr)is a fourth-generation conceptual *** an SCWr,the non-linear dynamics of the reactor require a controller capable of control-ling the *** this study,a pressure-tube-type SCWr was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled *** an SCWr,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power *** point kinetics equations with three groups of delayed neutrons were used in the ***-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous *** controlled parameters were reactor power,steam temperature,and ***,for these parameters,the PI controller had certain instabilities in the presence of *** classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering *** was highly accurate and stable and had a small computational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Higher order sliding mode controller Steam temperature Steam pressure Point kinetics model

Malargüe Site remediation:A Successful Solution for Uranium Mill Tailings

在线全文

学校读者我要写书评

暂无评论

原子能科学技术 2024年第10期58卷 2088-2094页

作者： BArArI E DíAZ J g gIOMIA KEMPF r A National Atomic Energy Commission Av.Del Libertador 8250Ciudad Autónoma de Buenos AiresC1429BNPArgentina

Comisión Nacional de Energía Atómica (CNEA) has the responsibility for restoring uranium mining facilities once the operations have ***,within its Environmental Program and in compliance with its legal responsibilities,decides to implement a restoration project for all sites related to the mining and processing of uranium *** Malargüe Site is located within the Province of Mendoza in the city of Malargü*** is the first site to successfully complete its *** activities consist of relocation of tailings to an engineering *** tailings management(encapsulation) and rehabilitation of the area was finished in June *** remediation alternative for the ore tailings was selected after conducting comparative studies and submitted the project to the society for *** objective of the encapsulation of the mineral tails is to isolate them from the environment,also proceeding with the decontamination and rehabilitation of the area (landscaping,post-closure monitoring and 20 years monitoring period).Encapsulation consisted of the construction of a containment cell for the mine tailings,to isolate them and prevent pollutants from entering the environment through the transfer *** clean the impacted areas,the soil was removed,it was incorporated into the encapsulation,and the filling was carried out with natural soils from the *** prevents radon transfer to the environment,as ^(222)ra is an alpha emitter with a half-life of four days,which produces its own radioactive *** progeny are solids,and when a ^(222)ra nucleus emits an alpha particle into the air,the resulting ^(218)Po nucleus,momentarily electrically charged,adheres to any dust *** prevents the discharge into the air containing radon and also containing dust particles charged with intensely radioactive radon *** tasks mentioned make it possible to decrease radon emanation,reduce radiological risks to the public and pre

关键词： remediation radionuclide transfer tailings encapsulation solution sustainable

Multi-objective method of selecting performance-based local climatic zones using binomial logistic regression in warm and humid climate

在线全文

学校读者我要写书评

暂无评论

Frontiers of Architectural research 2024年第1期13卷 184-200页

作者： g.r.Madhavan Dorairaj Kannamma Department of Architecture National Institute of TechnologyTiruchirappalliTamil Nadu 620015India

Urban agglomeration is a serious concern due to its high energy usage and impact on the local *** countries strive to determine the development path to optimize energy *** present study aims to examine the local climatic zones(LCZs)performance in warm and humid climate through a multi-objective approach for the residential *** performance is assessed by evaluating the urban microclimate and cooling load consumption for both summer and winter months using binomial logistic *** study concludes that LCZ 2_(3)(compact mid-rise with open low-rise)and LCZ 6_(B)(open low-rise with scattered trees)perform better for 80%and 50%of total hours in warm and humid *** also proves the presence of significant performance differences between mid-rise and low-rise *** intra-zonal differences between the climatic variables are higher than the inter-zonal differences due to the impact of land surface temperature(LST).The high aspect ratio and low sky view factor of LCZ 2_(3) help the residents in that morphology in enhancing better thermal comfort and reducing cooling load *** present study contributes to building regulation policymakers by providing information on the suitable morphology for warm and humid climate.

关键词： LCZ Outdoor thermal comfort Cooling load LST and urban morphology indicators

Three-stage pyrolysis–steam reforming–water gas shift processing of household,commercial and industrial waste plastics for hydrogen production

在线全文

学校读者我要写书评

暂无评论

Waste Disposal and Sustainable Energy 2024年第1期6卷 25-37页

作者： rayed Alshareef robert Sait-stewart Mohamad A.Nahil Paul T.Williams School of Chemical and Process Engineering University of LeedsLeedsLS29JTUK

Five common single plastics and nine different household,commercial and industrial waste plastics were processed using a three-stage(i)pyrolysis,(ii)catalytic steam reforming and(iii)water gas shift reaction system to produce *** of plastics produces a range of different hydrocarbon species which are subsequently catalytically steam reformed to produce H_(2)and CO and then undergo water gas shift reaction to produce further H_(2).The process mimics the commercial process for hydrogen production from natural *** of the single polyalkene plastics(high-density polyethylene(HDPE),low-density polyethylene(LDPE),and polypropylene(PP))produced similar H_(2)yields between 115 mmol and 120 mmol per gram *** though PS produced an aromatic product slate from the pyrolysis stage,further stages of reforming and water gas shift reaction produced a gas yield and composition similar to that of the polyalkene plastics(115 mmol H_(2)per gram plastic).PET gave significantly lower H_(2)yield(41 mmol per gram plastic)due to the formation of mainly CO,CO_(2)and organic acids from the pyrolysis stage which were not conducive to further reforming and water gas shift reaction.A mixture of the single plastics typical of that found in municipal solid waste produced a H_(2)yield of 102 mmol per gram *** the gas yields and composition from the single plastics enabled an estimation of the yields from a simulated waste plastic mixture and a‘real-world’waste plastic mixture to be *** different household,commercial and industrial waste plastic mixtures produced H_(2)yields between 70 mmol and 107 mmol per gram *** H_(2)yield and gas composition from the single waste plastics gave an indication of the type of plastics in the mixed waste plastic samples.

关键词： Waste plastic Hydrogen Catalyst Pyrolysis reforming Water gas shift

Fabrication and characterisation of random and aligned electrospun scaffolds to investigate hypothalamic stem/progenitor cell behaviour

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineered regeneration 2024年第1期5卷 11-20页

作者： Selina Beal Iain stewart Paul Hatton Marysia Placzek Ilida Ortega School of Clinical Dentistry and Insigneo Institute Claremont CrescentUniversity of SheffieldSheffield S102TAUK School of Biosciences University of SheffieldEnglandUK National Heart and Lung Institute Imperial CollegeLondon SW36LYUK

Tanycytes are stem/progenitor cells that reside in the hypothalamus of the adult vertebrate *** can be cultured as free-floating neurospheres in vitro but tend to spontaneously differentiate over *** we asked whether morphological cues provided by engineered polymer scaffolds can modify spontaneous ***-derived neurospheres were cultured on electrospun scaffolds,prepared with either random or aligned fiber *** dispersed widely on the scaffolds,and-on aligned scaffolds-were highly organized,orientated parallel to the *** analysis showed that cells cultured on aligned scaffolds showed significantly greater expression of the neural stem/progenitor cell marker,NrCAM and reduced expres-sion of differentiated cell markers in comparison to those cultured on random *** this shows that tanycytes respond to local engineered cues,and that a morphologically constrained environment can better main-tain tanycytes as stem *** aligned scaffold culture system provides a powerful tool to better investigate this novel stem/progenitor cell population.

关键词： Scaffold Tanycytes Neural stem/progenitor cells Fiber alignment Electrospinning

Nonlinear corrections for the nuclear gluon distribution in eA processes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第3期48卷 52-64页

作者： g.r.Boroun B.rezaei F.Abdi Department of Physics Razi UniversityKermanshah 67149Iran.

An analytical study with respect to the nonlinear corrections for the nuclear gluon distribution function in the next-to-leading order approximation at small x is *** consider the nonlinear corrections to the nuclear gluon distribution functions at low values of x and Q^(2) using the parametrization F_(2)(x,Q^(2))and the nuclear modification factors obtained from the Khanpour-Soleymaninia-Atashbar-Spiesberger-guzey *** CT18 gluon distribution is used for the baseline proton gluon density at Q^(2)_(0)=*** discuss the behavior of the gluon densities in the next-to-leading order and the next-to-next-to-leading order approximations at the initial scale Q^(2)_(0),as well as the modifications due to the nonlinear *** find that the QCD nonlinear corrections are more significant for the next-to-leading order accuracy than the next-to-next-to-leading order for light and heavy *** results of the nonlinear gLr-MQ evolution equation are similar to those obtained with the rausch-guzey-Klasen gluon upward and downward evolutions within the *** magnitude of the gluon distribution with the nonlinear corrections increases with a decrease in x and an increase in atomic number A.

关键词： gluon distribution nonlinear corrections light and heavy nuclei low x physics

Excellent photoluminescence and electrochemical properties of Sm^(3+) doped Ca_(2)MgSi_(2)O_(7) nanophosphor:Display and electrochemical sensor applications

在线全文

学校读者我要写书评

暂无评论

Journal of rare Earths 2024年第6期42卷 1046-1055,I0002页

作者： r.B.Basavaraj K.Sureshkumar D.P.Aarti M.B.Madhusudana reddy g.Nagaraju T.ramakrishnappa g.r.Navyashree K.r.Venkatesha Babu K.S.Hemalatha Department of Physics BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry School of Applied SciencesREVA UniversityBangalore560064India Energy Materials researchLaboratory Department of ChemistrySiddaganga Institute of TechnologyTumakuru57203KarnatakaIndia School of Physical Sciences REVA UniversityBangalore560057Indi Department of Physics Govt.Science CollegeBengaluru560001India Department of Physics Maharani Science College for WomenMaharani Cluster UniversityBengaluru560001India

A series of orange-red light emitting Ca_(2)MgSi_(2)O_(7):Sm^(3+)nanopowders were fabricated via low-cost ecofriendly green combustion technique using Aloe vera gel as *** phase purity of the samples were confirmed by the powder X-ray diffraction(PXrD)*** single-phase tetragonal structure is observed from the PXrD results with no additional impurity *** band gap energy of the fabricated powders was estimated by diffuse reflectance spectra(DrS)and is found to be in the range of 4.01-5.98 eV.A high resolution scanning electron microscope(SEM)was used to study the morphological behaviour of the ***-like structures are observed from the SEM *** particle size was evaluated by transmission electron microscopy(TEM)and is found to be~50 *** interplanar distance is found to be 0.53 *** properties were systematically studied in *** phosphors are successfully excited at 403 nm NUV light,producing reddish-orange characteristic *** emission peaks are centered at 558(^(4)g_(5/2)→^(6)H_(5/2)),607(^(4)g_(5/2)→^(6)H_(7/2))and 645 nm(^(4)g_(5/2)→^(6)H_(9/2)),*** the observed peaks the red emanation(^(4)g_(5/2)→^(6)H_(7/2))is stronger than the orange emission(^(4)g_(5/2)→^(6)H_(5/2))in the current *** photoluminescent concentration quenching is noticed above 5 mol%Sm^(3+)ion doping *** dipole-dipole interaction resulting in cross relaxation is found to be the principal cause of concentration quenching *** color features such as Commission Internationale de I’Eclairage(CIE)and correlated color temperature(CCT)were studied in *** optimized chromaticity coordinates were estimated to be(0.6363,0.3632),which fall in the reddish-orange *** average CCT value obtained is 3362 *** average color purity is found to be~82%.Sm^(3+)incorporated Ca_(2)MgSi_(2)O_(7) samples are possible contender for single white light generation commercial candidates owing to

关键词： green combustion Photoluminescence Orange-red emission Color purity Sensors rare earths